Tutorial by Examples: el
The loop macro has two forms: the "simple" form and the "extended" form. The extended form is covered in another documentation topic, but the simple loop is useful for very basic loop.
The simple loop form takes a number of forms and repeats them until the loop is exited using ...
let's generate a DataFrame first:
df = pd.DataFrame(np.arange(10).reshape(5,2), columns=list('ab'))
print(df)
# Output:
# a b
# 0 0 1
# 1 2 3
# 2 4 5
# 3 6 7
# 4 8 9
drop rows with indexes: 0 and 4 using drop([...], inplace=True) method:
df.drop([0,4], inplace=True)
...
DELETE FROM [dbo].[Customers]
WHERE CustomerName = 'Gorge';
INSERT INTO [dbo].[Customers]
([CustomerName])
VALUES ('George')
SELECT * FROM [dbo].[Customers]
Results
CustomerIDCustomerName10001Jerry10003George
Depending on the structure of your data, you can create variables that update dynamically.
DECLARE @CurrentID int = (SELECT TOP 1 ID FROM Table ORDER BY CreateDate desc)
DECLARE @Year int = 2014
DECLARE @CurrentID int = (SELECT ID FROM Table WHERE Year = @Year)
In most cases, you will want...
Example of setting the isolation level:
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
SELECT * FROM Products WHERE ProductId=1;
SET TRANSACTION ISOLATION LEVEL REPEATABLE READ; --return to the default one
READ UNCOMMITTED - means that a query in the current transaction can't access the...
#include <stdio.h>
#include <curl/curl.h>
int main(void)
{
CURL *curl;
CURLcode res;
curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
/* example.com is redirected, so we tell libcurl to follow redirect...
From emacs 24.4 package.el is avalable, and one way to install helm is to do it via MELPA. First, add the MELPA repository as package archive by putting following code somewhere in your ~/.emacs (or, ~/.emacs.d/init.el).
(require 'package)
;; add the repository before the package-initialize.
(...
template <class ForwardIterator>
ForwardIterator min_element (ForwardIterator first, ForwardIterator last);
template <class ForwardIterator, class Compare>
ForwardIterator min_element (ForwardIterator first, ForwardIterator last,Compare comp);
Effects
Finds the minimum element i...
The :only-child CSS pseudo-class represents any element which is the only child of its parent.
HTML:
<div>
<p>This paragraph is the only child of the div, it will have the color blue</p>
</div>
<div>
<p>This paragraph is one of the two children of the ...
Foreign keys enables you to define relationship between two tables. One (parent) table need to have primary key that uniquely identifies rows in the table. Other (child) table can have value of the primary key from the parent in one of the columns. FOREIGN KEY REFERENCES constraint ensures that valu...
Let's assume that we have one row in Company table with companyId 1. We can insert row in employee table that has companyId 1:
insert into Employee values (17, 'John', 1)
However, we cannot insert employee that has non-existing CompanyId:
insert into Employee values (17, 'John', 111111)
Msg ...
FOREIGN KEY constraint can be added on existing tables that are still not in relationship. Imagine that we have Company and Employee tables where Employee table CompanyId column but don't have foreign key relationship.
ALTER TABLE statement enables you to add foreign key constraint on an existing c...
This is a basic Hello World program in NASM assembly for 32-bit x86 Linux, using system calls directly (without any libc function calls). It's a lot to take in, but over time it will become understandable. Lines starting with a semicolon(;) are comments.
If you don't already know low-level Unix sy...
git clean -i
Will print out items to be removed and ask for a confirmation via commands like the follow:
Would remove the following items:
folder/file1.py
folder/file2.py
*** Commands ***
1: clean 2: filter by pattern 3: select by numbers 4: ask each
5: quit...
Introduction:
Swagger is a set of rules/specifications for a format describing REST APIs. It provides a powerful and actively developed ecosystem of tools around this formal specification like code generators and editors. The best part of Swagger is that the documentation of methods, parameters, an...
print "Hello World"
import clr
from System import Console
Console.WriteLine("Hello World")
While working on the development of an R package it is often necessary to install the latest version of the package. This can be achieved by first building a source distribution of the package (on the command line)
R CMD build my_package
and then installing it in R. Any running R sessions with p...
The getaddrinfo() function is the recommended POSIX function for interfacing with the system resolver. Depending on system configuration it will perform name lookups in the DNS, /etc/hosts, mDNS, etc.
It is preferred over the deprecated gethostbyname() family of functions because it supports both ...
